INCREASING DAILY DURATION OF REHABILITATION FOR INPATIENTS WITH SPORADIC INCLUSION BODY MYOSITIS MAY CONTRIBUTE TO IMPROVEMENT IN ACTIVITIES OF DAILY LIVING: A NATIONWIDE DATABASE COHORT STUDY

OBJECTIVE: To analyse the association between the daily duration of rehabilitation for inpatients with sporadic inclusion body myositis and improvement in activities of daily living, using a Japanese nationwide inpatient administrative claims database. METHODS: Data were extracted regarding inpatients with sporadic inclusion body myositis who had undergone rehabilitation between 1 April 2018 and 31 March 2021. The mean daily duration of rehabilitation was categorized into 2 groups: > 1.0 h (longer rehabilitation) and ≤ 1.0 h (shorter rehabilitation). The main outcome was improvement in activities of daily living from admission to discharge, measured using the Barthel Index. For the main analysis, a generalized linear model was used. RESULTS: In total, 424 patients with sporadic inclusion body myositis met the eligibility criteria for inclusion in the study. The main analysis found a significant difference in improvement in activities of daily living between the longer rehabilitation and shorter rehabilitation groups after adjusting for confounders (risk ratio (95% confidence interval), 1.37 (1.06–1.78)). CONCLUSION: A longer daily duration of rehabilitation results in improved activities of daily living for inpatients with sporadic inclusion body myositis.